Indicating device



Feb. 23, 1943.

Original Filed June 4, 1936 5 Sheets Sheet l INVENTOR. Wfi-a a'ozz5272475,

.9 @TTORNEY.

Feb. 23, 1943. w. 6. SMITH INDICATING DEVICE Original Filed June 4, 19565 Sheets-Sheet 2 INVENTOR. ydon 82224272, BY

Feb. 23, 1943. w s rr Re. 22,277

INDIGATING DEVICE Original Filed June 4, 1936 5 Sheets-Sheet 3 ll E-u-liINVENTOR. W'z'a, amz 5222175,

5 BY %RNEY Feb. 23, 1943. w. G. SMITH Re. 22,277

INDICATING DEVI CE Oiiginal Filed June 4, 1956 5 Sheets-Sheet 5 mil/lINVENT OR.

Reissued Feb. 23, 1943 INDICATING DEVICE William Graydon Smith, Concord,Mass., assignor to National Company, corporation of MassachusettsOriginal No. 2,060,537, dated November 10, 1936, Serial No. 83,579, June4, 1936. Application [or reissue August 1, 1942, Serial No. 453,235

11 Claims.

This invention relates to indicating devices generally. Moreparticularly this invention relates to a dial and/or similar mechanismadapted to be used as a micrometer caliper, radio tuning control and thelike, where a relatively accurate reading is desired.

An object of this invention is to provide a simple indicating mechanismemploying a pair of calibrated disc-like members angularly movable withrespect to each other at substantially the same peripheral velocity, andbeing arranged so that one of the disc-like members is positioned behindthe other so that the graduations of the rear member may be viewedthrough small windows provided in the front member as said members arerotated.

Another object of this invention is to provide a simple mechanismemploying a pair of disclike graduated or numbered members which areadapted to be movable angularly at least to a slight extent with respectto each other to indicate accurately the number of revolutions throughwhich a shaft, on which said disc-like members are mounted, is rotated.

Another object of this invention is to provide a dialing device adaptedto be mounted on or associated with a shaft to be rotated for rotatingsaid shaft through relatively small angles and for indicating therotation of said shaft by means of sets of Dre-arranged numbers andindicators carried by indicator elements movable with respect to eachother to a predetermined extent as said shaft is rotated.

A further object of this invention is to provide an adjusting andindicating mechanism adapted to rotate a shaft and indicate accuratelythe extent to which said shaft was rotated in the clockwise orcounterclockwise direction.

Other and further objects of this invention will be apparent to thoseskilled in the art to which it relates from the following specificationand claims.

In accordance with this invention I provide an indicating device ofsimple and efficient construction adapted to be used simply as ameasuring device, or as a computing device for combining readings on onedial and pointer device heretofore obtained from two or more dial andpointer devices, or as an accurate dial control device adapted toindicate the extent of rotation of a shaft. r

l have illustrated and described several embodiments of the indicatorarrangement of my invention, all of which will be more clearlyunderstood lrom the following specification.

The indicator device set forth herein includes Inc. Maiden, Mass, at

two rotatable or movable members which cooperate to produce the correctindication of the shaft being rotated. The shaft being rotated is eitherattached to one of the movable members or geared thereto and rotation ofthe shaft transmits motion either through the latter member or throughsuitable gear or gears to the other of said rotatable or movablemembers. These two members are provided with graduations and/or scaleswhich are shifted in a predetermined manner with respect to each other,through the operation of the rotated shaft or through the operation ofone of the members, adapted to rotate said shaft, and the extent throughwhich the shaft is rotated or the revolutions imparted thereto, areindicated or may be easily determined from said graduations and/orscales. One of the rotatable members is positioned in front of the otherand is provided with a series of small windows through which successiveparts of the scales or graduations of the rear rotatable member arebrought into view.

The preferred embodiment of my invention employs two disc-like members,each provided with gear teeth. The gear teeth of one of these disc-likemembers are adapted to mesh with the teeth of the other member. Rotationof one member, therefore, causes the other to rotate also. However,these members, being eccentrically mounted with respect to each otherand having an unlike number of teeth, do not rotate at the same angularvelocity although the peripheral velocities of the aforesaid smallwindows of the front rotatable member and the scales or graduations ofthe rear rotatable members are the same. The graduations or scalescarried by the rear disc-like member are, however, caused to shift inposition with respect to the aforesaid windows and indicate the rotationor revolution of the shaft.

One of the embodiments of this invention shows one of the disc-likemembers provided with a knob and fastened to a shaft for the purpose ofrotating this shaft and a reduction gear arrangement. This embodiment ofthe invention is particularly adapted to be employed for controlling thetuning of signaling apparatus. It is, however, to be understood thatthis invention is not limited to use with tuning controls and that thisillustration of the use thereof is only by way of example.

Further details of this invention will be set forth in the specificationand the drawings in which, briefly, Figure 1 shows a front view of theindicating and control mechanism; Figure 2 shows a top view of theindicating and tuning control; Figure 3 and 4 are views showing one ofthe indicator dials in front and side elevation; Figures 5 and 6 showthe inner indicating dial in front elevation and cross-section,respectively; Figures 7 and 8 are views illustrating the inner surfacesof the dial shown in Figures 3 and 4; Figure 8 is a sectional view takenalong the line 'l--| of Figure 7; Figure 9 is a sectional view takenalong the line 99 of Figure 2; Figure 10 is asectional view of the knobemployed on the control, showing this knob attached to the front dial;Figures 11 and 12 are views illustrating the worm gear and shaft;Figures 13 and 14 are sectional views along the lines l3|3 and l4l ofFigure 12, respectively; Figure 15 is a section through the worm gearsalong: the line ldtfl of Fig. 9; Figure 16 is a diagram illustrating theprinciple of operation; Figures 17 and. 18 illustrate modified forms ofthe dial indicating mechanism of this invention; and Figures 19 and. 20are sectional views along the lines |9-l9 and 20-20 of Figures 1'? and18 respectively;

Referring to the drawings in detail. particularly Figure 1, referencenumeral t8 designates the front graduated mask or dial having five smallholes ll, Ila, Nb, 0,. and lid formed adjacent to the periphery thereof.The periphcry of this dial Ill is graduated, and graduations l4, evenlyspaced, are engraved, embossed, printed, etched, or otherwise placedupon the beveled surface adjacent to the circumference of the dial. Thewindows ll, Ila, Ho, Ho, and d are equally spaced around the dial, tengra'duations apart. A pointer I2 is attached to the panel I3 near thetop of the dial Ill and forms a pointer or indicator. A knob H isscrewed, bolted, or otherwise attached to this dial to facilitate;rotation thereof.

This dial mechanism is placed on the front of the panel I3 and is heldthere by a shaft and bearing arrangement, described in followingparagraphs of this specification. Behind" the panel 83 a gear box IE ispositioned. This gear box supports a shaft upon which the devices" to becontrolled are mounted. For purposes of Mine-- tration a tuningcondenser 22 is shown mounted on one side of the gear box [5. Several ofthese units or similar units may be mounted on the shaft It to becontrolled in accordance with the operation of the dial knob M, ifdesired. The condenser in the present case is provided with rotor andstator plates l8 and I9, respectively. The stator plates are held inspaced relation upon the grooved or notched supports 20 the ends ofwhich are attached to insulation supports 2| and Zia. An insulationplate or panel 25, to which the support 2| is attached, is bolted to theside of the gear housing l5 by means of the members 24, the threadedends of which extend into threaded holes formed in the side of the gearhousing, through suitable holes formed in the insulation member 25. Therotor plates is are held in a hollow-grooved-cylindrical support ll,properly spaced. One end' of this supporting member H is engaged by awiping resilient contact member 23 for the purpose of forming electricalcontact with the rotor plates through this support. A suitable sleeve 26is positioned over the shaft I 6 and supports the: member I! on theshaft electrically insulated therefrom. The sleeve may be of anysuitable insulation material, such as, fiber, Bakelite, hard rubber. andthe like, which is somewhat deformable. The set screws 21 are providedto threaded holes in the support I! for the purpose of fastening thistubular support over the insulation sleeve 26 and the shaft I6. Asubstantially rigid end plate 28 is attached to the ends of the members24 by suitable bolts 29. An insulation bearing member 35 is supported inthe end plate 28 in en- Basement with the end of the shaft It. Thisinsulation bearing carries a ball bearing inside thereof and is providedwith a screw adjustment for thrusting said ball bearing against the endof said shaft. A piece of insulation material similar to the insulator2|, made of material such as synthetic porcelain, porcelain, glass,hero-silicate glass, fused quartz, or the like, having good insulatingproperties for relatively high frequency electric currents, is attachedto the ends of the stator supports 20 and to the end plate 28 to provideadditional supporting means for the said stator plates. One or morevariable electrical condenser units such as, the condenser 22, may bemounted on each side of the gear box 15, in a tandem arrangement, ifdesired. However, if only one unit is to be used, then the shaft I6,shown extending to the left of the gear housing I5 is out off adjacentto said housing.

The dial HI and the dial 40, which is positioned inside of the dial ID,are illustrated in detail in Figures 3-, 4, 5, and 6. These dials areassembled and held together by two small springs 60, shown in Figure 9.The dial ID is provided with a centrally-located shaft-receiving section3!, the forward end of which is provided with two small notches 34 whichreceive the hooks 6| of the springs 60. These springs are passed throughthe holes 33 formed in the section 35 and the hooks 62, formed at theother ends of the springs, brought into engagement with the smallprojections 45 formed in the disc 40, as shown in Figures 5, 6, and 9.When the disc-like dials HI and are assembled. the notches 34 and theprojections must be in alignment and the numher. 250 must appear visiblethrough the window or hole H, as will be described in more detailfurther in the specification.

The central portion of the disc 40 is provided with 3 holes 46. Portionsof these holes are in alignment with the holes 4! provided to thedisclike dial I0. These holes are made to provide access to and receivesmall bolts which are used to attach the knob M to the front dial Ill asillustrated in more detail in Figure 10. A set screw 32 is provided tothe dial II! for the purpose of attaching this dial to the shaft 16,shown in Figures 9, 11, and 12.

A ring-like gear is provided to the inside of the dial ill asshown inFigures 7 and 8. This gear is made to mesh with the gear 43 of the dialon, when the two dials are assembled as in Figure 9.

After the two dials are assembled and held together by the spring asaforesaid, the dial assembly is placed over the end of the shaft Ill andthe hole 42 of the dial is placed over the eccentrically disposedsection II of the bearing member I2. This bearing member is attached tothe gear casing l5 by small bolts 13 and projects outward from the frontside of this gear casing. A spring 14 abuts against the inner surface ofthe bearing 12 and also against the bearing Washer 15 which ispositioned adjacent to the ball bearing housing 16. The housing 16encloses and forms a race for ball bearings 11 and abuts against theshoulder 18 formed on the shaft Hi. The worm 19 is formed integral withthe shaft and made to mesh with the worm wheels and 9|, as shown inFigs. 9 and 15. The end B0 of the shaft Til is pointed and extends intothe hole 8| of a thrust bearing, formed in the projection 92 on theinside of the housing l5. This hole forms a bearing surface for theshaft I9, serving to keep the worm gears in mesh, and the inner portionthereof may be made larger than the shaft point to permit grease to bepacked therein.

When the worm gear 19 is placed in the housing 85 in mesh with the wormwheel 99, the bearing member I2 must be pressed into engage ment withthe side of the housing IS in such a way that the lug or projection 12a.fits into a slot 12b formed in the wall of said housing. When this lug12a is received in the slot 12!) the section H which is eccentricallydisposed with respect to the shaft 19 assumed its proper position withrespect to said shaft. This is the same position as the shaft hole ofthe dial Ill and the hole 42 of the dial 49 have with respect to eachother when the scale number 250 is visible through the hole II, as shownin Fig. 1. The number 259 is one of the scale numbers on the scale H ofdia] 40, Fig. 5.

The relation of the shaft 19 and the section I I, which is eccentricallydisposed with respect to this shaft, is shown in more detail in Figure14, which is a cross-section taken along the line i4-i4 of Figure 12.The dial i9 is attached to the shaft 19 adjacent to the section II, bymeans of the set screw 32 and is adapted to rotate this shaft when theknob I4. attached to the dial, is rotated. The dial 49, which ispositioned substantially inside of the dial lli, fits over the sectionll. rather snugly, and when the dial i9 and shaft 19 are rotated, thiseccentrically disposed section H causes the dial 49 to oscillate withrespect to the dial If]. This causes an angular displacement or a slightrotation to take place between the dials i9 and 49 through the operationof the gears 59 and 43.

The worm wheels 99 and 9! associated with the worm 19 are mounted insideof the housing l5 on the shaft 16 which extends through the housing andis mounted in bearings formed in the sides of the latter. The worm wheel99 is provided with two lugs 92 and 93 which cooperate with a similarlug 94 formed in the inside of the top l5a, to limit the rotation ofthis worm wheel 90 substantially to one-half revolution thereof. Thepurpose of this will be more fully explained in the operation of thisdevice. Several springs 96 attached to small lugs 91 provided to theworm wheel 99 are also attached to similar lugs 98 formed on the wormwhee] St.

The purpose of these springs is to shift the r worm wheels 90 and 9|with respect to each other slightly as these worm wheels are wornthrough engagement with the worm 19. Thus these springs serve to take upbacklash that may otherwise be developed through the wearing of the wormgears after a certain period of normal use. These springs are adjustedto exert a slightly shearing action upon the teeth of the worm 19, thatis, the teeth of the worm wheels 99 and 9| tend to shear the teeth ofthe worm 19 to a slight extent. This shearing action must not be madetoo great, otherwise undue wear will be placed upon the teeth of theworm gears.

The gear housing I5 is provided with a cover i5a, attached in anyconvenient manner, as by suitable bolts, to the body of the housing.When it is desired to gain access to the gears 99 and 9|, this cover I5amay be removed. The gear 99 is fastened to the shaft l6 by means of oneor more set screws 95. The gear 9| is not attached to the shaft it byset screws or otherwise except through the springs 98 and the gear 99.The shaft "5 may be removed from the housing [5 by loosening the setscrew and by loosening the set screws 26 of the condenser 22 shown inFigure 2. The housing I5 is preferably packed with grease to a slightextent so that the worm gears and the bearings of the shaft I9 areproperly lubricated to reduce wear to a minimum.

Referring now particularly to Figs. 3 and 5. I shall describe the mannerin which the dials are marked in the example shown and the resultantoperation. In the example this marking is in accordance with the decimalsystem of numerical notation and the movement of the condenser from oneextreme to the other of its finite range is arbitrarily divided into 500parts which are effected by ten revolutions of the shaft I9 (Fig. 9),that is, ten manual revolutions of the knob l4. Thus each revolution ofthe shaft represents a simple fraction, one-tenth, of the range of theinstrument. It will be noted that this range is a non-recurrent rangeand there are thus five hundred and one designated positions ofadjustment with an end point 0 at one extreme of the range and an endpoint 500 at the other. Having reached, say, the point 500 to commence anew traverse from zero, we must first retrace our steps theretobackwardly throughout the range. Each revolution of the shaft,corresponding to one revolution of the dial l9, effects a movementthrough fifty points in the range and therefore the.dia1 l9 may havefifty peripheral graduations 14, each one of which may be brought intoopposition to the stationary index or orienting point 12 (Fig. 1)exactly to determine the position of the mechanism being adjusted. Todesignate cardinal points in the range, herein every multiple of ten,the inner dial 49 (Fig. 5) is suitably inscribed with numeralsexpressive of such multiples, which numerals are in operationselectively exposed through the apertures II and as regards the aperturewhich in operation is moving past the index I2 expresses the number ofincrements of motion which have been impressed upon the mechanism, aswill hereinafter appear. For this purpose five apertures l I equallyspaced circumferentially are provided and, as seen in Fig. 5, inadjacent circumferential segments of the bevelled periphery of the dial49 five series of numerals. Each series forms an arithmeticalprogression, the common difference in each of the progressions beingfifty, and the initial terms of the progressions, proceeding herein in apositive direction of rotation or counterclockwise, as 0, 10, 20, etc.in themselves form an arithmetical progression.

At the upper portion of Fig. 5 will be noted the numeral 0 and thenumeral 500 indicative of the end points of the movement, one or theother of which might be considered a superhumerary number. In otherwords, we have fiftyone numerals, multiples of ten, expressing cardinalpoints of the range of five hundred positions including the two endpoints.

It will be understood that the gear ratio is such that, if we startinitially at the indication 0, ten revolutions of the shaftcorresponding to the complete range of the instrument will bring thenumeral 500 to the same position, the relative movement of dial 49 withrespect to dial I 0 being less than one full revolution. At intermediatepoints successive revolutions of the shaft will bring to substantiallythe same position homologous elements of the several sets of numerals.For instance, if we start at 250, as shown in Fig. 5, which may beconsidered the sixth element of the arithmetical progression whichbegins with and has the common difference fifty, one-fifth of arevolution will bring to substantially the 12 o'clock position shown thenumeral 260, which is the sixth element of the progression beginningwith 10, two-fifths of a revolution will bring to the 12 o'clockposition the numeral 2'70, the sixth element of the series beginningwith 20. The complete revolution starts a new cycle with 360, theseventh element of the first series.

Now, with the parts in the position shown in Fig. 3, let us suppose thatwe wish to adjust the mechanism to the position designated by thenumeral 256. We turn the knob clockwise. The outer dial l0 rotates and,the peripheral speed of the two dials being substantially the same atthe 12 oclock position, the whole system with the inscriptions exposedthrough the apertures which are within the view of the operator appearsto move as a unit and we turn the dial to the sixth graduation to theleft in customary manner. The effect, particularly because the lowerapertures, past which the numerals would be seen moving rapidly, areconcealed from the normal vision of the operator by the knob and theoperators hand which grasps the knob and the fact that they are on thedownwardly facing bevelled edge of the dial and thus not presented tothe eye, is that of turning a simple dial inscribed with fiftygraduations, every tenth graduation being numbered. However, if we wishto pass to 495, corresponding to 245 units of adjustment, we wouldrapidly twirl the dial in our fingers. By virtue of the constructiondescribed the inscriptions in the windows coming up from the left wouldappear as stationary inscriptions numbered with multiples of ten and bythis quick and rapid movement we would reach 490 and then by a slowermovement move the desired graduation 14 indicative of five units intooppoition to the index l2. The operation would stop at the extreme point500or at the extreme point 0 in the other direction.

We are Working with a dial marked with fifty widely spaced graduationsbut which is always in effect inscribed with numerals expressive of theparticular group of 50 in the range of 500 in which we are operating.The practical effect is as if our dial had five hundred and onesimilarly spaced graduations. Expressed otherwise, if our dial is fiveinches in diameter, our scale of five hundred units is about thirteenfeet long. Because of the eccentric relation of the parts the linearspeed of the numerals and the apertures is substantially identical atthe upper part of the dial, and while a number moves across an apertureon each revolution of the shaft HI the motion may be said to bepractically imperceptible to the eye in the upper quadrant, say from the:30 oclock to the 1:30 o'clock position, and is indeed hardly noticeablethroughout the upper half of the circumference.

It is, of course, obvious that different calibraiions of these dials maybe employed in accordance with this invention. For example, a greater orlesser number of holes may be employed in the dial l0 and differentgraduations and scales may be employed on the dial 40. I have shown twovariations of this dial employing different calibrations and differentscale arrangements, in Figures 1'7, l8, l9, and 20. Corresponding partsof these figures are designated by the same reference numerals asemployed in the previous figures. In these embodiments of this inventionthe dials I I] and 40 are mounted behind the panel l3 and are drivenfrom the shaft 10. No knob for rotating the dials is shown on the frontof the panel although it is obvious from the showing in the previousfigures that this may be provided, if desired. At the same time thedials may be driven from the shaft of the electrical instrument withwhich they are associated and the electrical instrument may becontrolled by other than manual controls.

The dial I0 is attached to the end of the shaft 10 by means of asuitable bolt lllc fitted into said shaft. A small gear adapted to meshwith the peripheral gear teeth of the dials HI and 40 is mounted uponthe pin l6 which is carried by the arm lBg. This arm is attached to thepanel by means of a suitable bolt l3c and extends to the shaft 10.

The section lBk of the arm I69 corresponds to the member I2 shown inFigures 11 and 12. This section lGk is provided with a section 401)which is eccentrically disposed with respect to the shaft 10 insubstantially the same manner as the section H is eccentrically disposedwith respect to the shaft 10 of Figures 11 and 12, The dial 40 issupported on the section 401) which forms its bearing.

An elongated Window l3a is formed in the panel I3 permitting the scaleof the dial 40 and the holes H, Ha, ll, lla., He, II and Hg of the dialIII to be viewed as these dials are rotated through the operation of theshaft 10 and the pinion gear "ii.

In this form of the invention the dial H! is smaller than the dial 40and rotates faster than the dial 4!) inasmuch as these dials are rotatedby gear teeth formed in their peripheries. The dial 4!! is also providedwith a scale 4| comprising a series of numbers, including the numbers 1to 25. The numbers 1 and 2 are spaced ten divisions apart, are are allof the succeeding consecutive numbers up to and including the number 25.The dial ID, in this case, is provided with eight holes such as the holell. These holes permit the numbers from the scale of the dial 40 to bebrought into view in their consecutive order; for example, if the number1 is visible in the hole II, the next number that will be visible in thesucceeding hole, the dials are rotated, will be number 2 and so on,until the number 25 is rendered visible at the top of the dials throughthe elongated hole Kid.

The rinciple of operation of this embodiment is the same as that of theembodiment previously described.

The embodiment of this invention shown in Figures 18 and 20 differs fromthat shown in Figures 17 and 19in that the shaft 10 is provided with asmall pinion gear lBa engaging the gear llib which is mounted upon thepin I and drives the small pinions lid and lBd'. These small pinions Ndand l6d engage the peripheral gears Illa and 40a. of the dials Ill and40 respectively. These dials I0 and 4B are also eccentrically mountedwith respect to each other, the member 40c being provided for thispurpose. This member 400 is attached to the panel l3 by means of thesmall bolt I00 and is provided with two bearing surfaces lllb and 402)which engage the dials Ill and 48 respectively. The bearing surface 40!)is eccentrically disposed with respect to the bearing surface In. Anauxiliary scale I00, partially visible through the hole He: in

the panel I3 and the hole I! of the dial "I, is employed in thisembodiment in place of the graduations I 4 on dial Ill, Figure 3.

The operation of the embodiment of this invention shown in Figures 18and 20 is similar to that of the other embodiments of this invention. Inthis case, however, the hole I l passes over the graduations or scale Ias the dial Ill is rotated. For example, when this dial I0 is rotated inthe clockwise direction and the number 13 on the dial I0 is visiblethrough the hole i I, the reading shown through this hole II, as thishole is brought into view in the window l3a, will be 130 near left endof said'window and increase in steps of one to 131, 132, 133, 134, andso on up to 139, as the hole ll passes out of view under the panel [3 atthe right end of said window. The next hole to the left of the hole IIwill then come in view and exihibit the number 140 at the left end ofthe window I3a. As the dial is rotated further in the clockwisedirection, the reading increases to I49 and the next hole is broughtinto view at the left end of the window [3a giving the reading 150 andso on.

It is obvious that the embodiments of this invention shown in Figuresl7, 18, 19, and 20 may be employed in conjunction with the embodiment ofthis invention shown in Figures 2 and 9, with other than manual controlsshown therein. Different forms of drive mechanisms may be employed fordriving or imparting angular motion to the dial or" indicator devices.

While I have described my invention in detail with respect to theembodiments set forth herein, it is, of course, understood thatmodifications thereof may be made without departing from the spirit andscope of this invention. I therefore do not desire to limit thisinvention to the exact details described and shown except insofar asthose details may be defined by the following claims.

What I claim and desire to secure by Letters Patent of the United Statesis as follows:

1. In means for delicately adjusting a member back and forth over anon-recurrent range, in combination with a driving means, a rotatableshaft moving therewith and making a whole number of revolutions incovering said range, a dial carried by the shaft having graduationscorresponding to simple fractions of a revolution for cooperation withan index to determine the adjustment of the member, the dial also havingapertures therein, and a second dial masked by the first but observablethrough said apertures and having thereon a scale comprising sets ofnumerals, each of which forms an arithmetical progression, the commondifference being the same in the several progressions, the firstelements of the sets in themselves forming an arithmetical progression,the scale including separate numerals corresponding to the end points ofthe range of said member, the two dials being geared together to exposehomologous numerals of successive groups at one of said openings onsuccessive revolutions of the shaft.

2. In means for eifecting a delicate adjustment of a mechanism, adriving shaft geared thereto for effecting a relatively slow movement ofthe mechanism and manually operable means for turning the shaft, onerevolution of the shaft corresponding to a simple fraction of adetermined movement of the mechanism, a dial moving with the shafthaving graduations corresponding to a simple fraction of the firstfraction to be brought into opposition to an index to determine theadjustment of the member, said fractions representing sub-units of asystem of numerical notation, the dial also having apertures therein,and a second dial masked by the first but observable through saidapertures and having thereon a scale comprising sets of numerals, eachof which forms an arithmetical progression, the common difference beingthe same in the several progressions, the first elements of the sets inthemselves forming an arithmetical progression, the two dials beinggeared together to expose homologous numerals of successive groups atone of said openings on successive revolutions of the shaft.

3. In a means for eifecting a delicate adjustment of a mechanism, adriving shaft geared thereto for effecting a relatively slow movement ofthe mechanism, a knob on the shaft for manually turning the same, acircular dial inward of the knob having peripheral graduations adaptedto be brought into cooperation with an index to determine the adjustmentof the member, said dial having spaced apertures around the peripherythereof, a rotatable dial rearward of the other having numeralsexpressive of movements corresponding to passages of a multiplicity ofsaid graduations past the index, said dials being geared together toeffect a differential rotative movement therebetween to expose a numeralindicative of the actual movement of the first dial at an apertureexposed for view at one side of the knob and the manipulating hand, thedials at that location moving at substantially equal linear velocitiesduring their rotating movements.

4. In a means for effecting a delicate adjustment of a mechanism, adriving shaft geared thereto for effecting a relatively slow movement ofthe mechanism, means for rotating the same, a rotatable circular dialhaving a bevelled edge provided with graduations adapted to be broughtinto cooperation with an index to determine the adjustment of the memberand having apertures intersecting the bevelled portion spaced around theperiphery, a dial inwardly of the other having a bevelled edgeunderlying, the bevelled edge of the first, the edge of said second dialbeing inscribed with numerals expressive of movements corresponding topassages of a multiplicity of said graduations past the index, saiddials being geared together to effect a differential rotative movementtherebetween to expose a numeral indicative of the actual movement ofthe first dial centered behind one of said apertures, the dials at thatlocation moving at substantially equal linear velocities during theirrotating movement, whereby an observer looking down at said aperturewill observe little movement of the indication as the dials turn whereasuncentered numerals at the opposite sides of the dials are faced awayfrom his observation on account of the bevel of the edges.

5. In a means for delicately adjusting a member back and forth over afinite range in combination with a driving means, a rotatable shaftmoving therewith and making a whole number of revolutions in coveringthe range, a dial carried by the shaft having graduations forcooperation with an index extending around its circumference in acontinuous series, the dial also having equally spaced aperturescorresponding to cardinal points in a scale determined by suchgraduations, and a second dial masked -by the first and geared to rotatethrough a smaller angular distance than the first and having thereonmarkings arranged for observation in serial order through a selected oneof said apertures as the dial is rotated, said markings being expressiveof the serial cardinal divisions of the range and being in number onegreater than the product of the number of apertures and the number ofwhole revolutions made by the dial in covering the range, whereby toprovide an identification of every cardinal point in said finite rangeincluding the end points.

6. In a means for delicately adjusting a member back and forth over afinite range in combination with a driving means, a rotatable shaftmoving therewith and making a Whole number of revolutions in coveringthe range, a dial carried by the shaft having graduations forcooperation with an index extending around its circumference in acontinuous series, the dial also having equally spaced aperturescorresponding to cardinal points in a scale determined by suchgraduations, and a second dial masked by the first and having thereonmarkings denoting the serial cardinal divisions of the range, saidsecond dial being geared to the first to rotate through a smallerangular distance and making, as the member is moved through its range,less than one full revolution relatively to the first dial to expose themarkings in serial order at a selected one of the apertures.

7. In means for indicating the adjustment of a mechanism, a shaftconnected thereto to make a multiplicity of revolutions when themechanism moves through its range, a dial on the shaft having markingsindicative of successive equal fractional rotations thereof, whichmarkings are adapted to be brought into opposition to an orientingpoint, a second dial having inscriptions designating decimal multiplesof said fraction positioned to be moved past said orienting point, andmeans gearing the dials together to move at different angular speeds butwith substantially the same constant linear speed past the orientingpoint to provide at said point an indication of the position of theparts expressed in terms of such fractional revolution in units andmultiples thereof.

8. In means for indicating the adjustment of a mechanism, a shaftconnected thereto to make a multiplicity of revolutions when themechanism moves through ts range, a dial on the shaft having markingsindicative of successive equal fractional rotations thereof, whichmarkings are adapted to be brought into opposition to an orienting pointand having spaced apertures adjacent such markings, a second dial behindthe first having inscriptions thereon designating decimal multiples ofsuch fraction, said inscriptions being in circumferentially adjacentgroups, each group constituting an arithmetical progression, theindications positioned to move past said apertures, and means gearingthe dials together to move with different angular speeds but atsubstantially the same linear speed at the orienting point, whereby themarkings and inscriptions cooperate to give an indication at that point.

9. An indicating device comprising a .pair of scale carrying members,means for rotating said members with respect to each other, one of saidmembers being disposed in front of and substantially completely maskingthe other, means in the front one of said members for permitting theviewing of selected portions of the scale of the other of said members,said last mentioned scale comprising numerical designations so arrangedthat succeeding elements thereof brought into view during the movementof said members continually indicate the extent of said rotation.

10. A combined indicator and control unit comprising a pair of disc-likedials comprising a first dial and a second dial, said first dial beingpositioned in front of said second dial, indicia on the first dial formanifesting the incremental angular movements thereof, numerical scalesfor said second dial, said first dial having means for viewing thescales of said second dial, a rotatable shaft, means for fastening saidfirst dial to said shaft, a bearing member for said second dial disposedeccentrically with respect to said shaft, means for rotating said firstdial and said shaft. means for rotatively driving said second dial fromsaid first dial at a different angular velocity for exhibiting differentparts of the scales of said second dial through said scale viewing meansfor indicating the extent of rotation of said shaft, and means for saidfirst mentioned rotatable shaft for driving a variable electrode unitfor transmitting the effect of angular motion of said first mentionedshaft to said variable electrical unit.

11. A combined indicator and control unit for variable condensers andlike apparatus comprising a disc-like dial, a knob for said dial, ashaft for transmitting motion to the apparatus, means for attaching saiddial to said shaft, said dial having a plurality of graduations aroundthe periphery thereof and a plurality of holes equally spaced adjacentto the periphery thereof, a second disc-like dial positioned back ofsaid first mentioned dial, numerical scales for said second dial adaptedto be viewed through said holes, means for rotating said second dial assaid first dial is rotated at a slightly different angular velocity forbringing different parts of said scales into view in selected ones ofsaid holes for indicating the rotations of said first mentioned dial andshaft, and means for attaching a variable electrical device to saidshaft for varying said variable electrical device through anon-recurrent range in accordance with the rotation of said knob.

WILLIAM GRAYDON SMITH.

CERTIFICATE OF CORRECTION. Reissue No. 22,277. February 25, 19115.

WILLIAM GRAYDON SMITH.

It is hereby certified that error appears in the printed specificationof the above numbered patent requiring correction as follows Page 6,sec- 0nd column, line 55, for "electrode" read --electr1c-- and that thesaid Letters Patent should be read with this correction therein that thesame may conform to the record of the case in the Patent Office.

Signed and sealed this 15th day of April, A. D. 191;}.

Henry Van Arsdale,

(Seal) Acting Commissioner of Patents.

